20860409 has 2 divisors, whose sum is σ = 20860410. Its totient is φ = 20860408.

The previous prime is 20860403. The next prime is 20860451. The reversal of 20860409 is 90406802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17808400 + 3052009 = 4220^2 + 1747^2 .

It is a cyclic number.

It is not a de Polignac number, because 20860409 - 2⁴ = 20860393 is a prime.

It is not a weakly prime, because it can be changed into another prime (20860403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10430204 + 10430205.

It is an arithmetic number, because the mean of its divisors is an integer number (10430205).

Almost surely, 2^20860409 is an apocalyptic number.

It is an amenable number.

20860409 is a deficient number, since it is larger than the sum of its proper divisors (1).

20860409 is an equidigital number, since it uses as much as digits as its factorization.

20860409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 20860409 is about 4567.3196735066. The cubic root of 20860409 is about 275.2797549807.

The spelling of 20860409 in words is "twenty million, eight hundred sixty thousand, four hundred nine".